This method most particularly finds its application within the scope of producing renewable energy from solar light.
PSII is a photosensitive enzymatic molecular complex comprising pigments (chlorophyll) which is the centre of water hydrolysis in the chloroplasts present in the cytoplasm of plant cells according to the following reaction:

wherein hv corresponds to a light photon, for example of solar light, H2O is water, H+ represents a free proton and e represents a free electron.
The enzymatic complex PSII, because of its hydrolyzing function, produces from light, oxygen on the one hand, and free electrons and free protons on the other hand, is of a particular interest within the scope of its use for producing, via a cathode, a clean fuel which is hydrogen gas (as a gas under standard temperature and pressure conditions). Indeed, the cathode gives the possibility of recombining the e− and the H+ (reduction reaction of protons) in order to form the hydrogen. With this in mind, this enzymatic complex is a promising actor for producing clean fuel, i.e. the combustion of which is not associated with the production of CO2, from natural energy: light, which furthermore is a quasi-inexhaustible source of energy.
Consequently, hydrogen gas, resulting from the reduction of the free protons which are associated with the free electrons, combines to oxygen resulting from the hydrolysis reaction in order to produce a combustion reaction, which results in production of energy on the one hand and of water on the other hand which may be again hydrolyzed by the PSII complex, so that a water cycle is formed, thereby forming a quasi-inexhaustible source of clean fuel. Further, the oxidation assisted by the PSII complex allows the formation of oxygen and hydrogen in situ, and is an answer to the present problematical question of the conditioning of hydrogen which, when it is formed in situ, no longer requires being stored under limiting packaging forms such as those known presently: large volumes, significant pressures, etc.
According to the document Biochimica et Biophysica Acta 1817 (2012) 1028-1212, there are successive absorptions of photons of light by the pigments of PSII. To each absorption corresponds a chemical oxidation-reduction reaction which takes place in the enzymatic complex PSII. Moreover it is known from the state of the art that the successive absorption of four light photons by the pigments of PSII exclusively allows successive achievement of four oxidation-reduction reactions forming a photochemical cycle (Kok cycle) at the origin of the oxidation of water into oxygen, on the one hand, and into free protons and free electrons on the other hand.
Moreover, it is known from the state of the art that the activity of the PSII complex is inter alia regulated by that of the PSI complex.
The activity of PSII is measured by the production rate of oxygen in the water, the higher this rate, the higher is the yield of the water oxidation reaction by PSII, i.e. the higher is the amount of produced oxygen.
Indeed it is known that, the presence of the PSI complex, because of its function in the mechanism for producing energy by photosynthesis, consumes the free photons and electrons indirectly intended subsequently for the reaction of synthesis of sugars by polymerization of CO2.
It is therefore advantageous that the PSII complex is insulated from the PSI complex so that the water oxidation reaction increases in yield. In practice, the PSII complex is isolated from the PSI system, the latter being replaced by a sensor (device, product, material) or a group of electron and proton sensors which have the property of not inhibiting the activity of PSII. As an example, the electron and proton sensor may also be a cathode allowing reduction of the protons into hydrogen gas.
By the term of «isolated» is meant in the sense of the disclosure that the PSI complex is not able to cooperate with the enzymatic complex PSII.
In the aforementioned method, the activity of the PSII is mainly limited by the concentration and the nature of the electron sensors and proton sensors or electron and proton sensors which, for example react with the free protons and the free electrons in order to undergo reduction.
This aspect is moreover underlined in the article of Sheleva and Messinger mentioned at the beginning and wherein the authors demonstrate the efficiency of the turnovers for an enzymatic complex PSII according to the chemical nature of the electron sensors.
By the term of «turnovers» should be understood the number of steps of each looped Kok cycle per unit time, it being understood that a full Kok cycle comprises four successive turnovers since it is associated with consecutive absorption of four protons of light.
During the interaction of light with the enzymatic complex, a first charge separation S0→S1 takes place and is followed by three other charge separations S1→S2, S2→S3, and S3→S4. With each of these charge separations is associated an oxidation-reduction reaction of the Kok cycle with, when the cycle is a closed loop, formation of oxygen and of free protons as well as free electrons, and the return of the complex from the state S4 to the state S0.
In particular, the authors demonstrate that one of the four oxidation-reduction reactions of the Kok cycle: the reduction reaction, governed by the reactivity of the electron sensor, is the limiting step of the Kok cycle.
Also, Sheleva and Messinger suggest that the yield of the enzymatic complex PSII may be optimized by selecting a predetermined pulse frequency value which is a specific pulse frequency of the pulsed light associated with a predetermined reduction reaction rate which occurs in the immediate environment of the electron capture group of the enzymatic complex PSII.
In this way, to a specific electron sensor corresponds a specific pulse frequency: the question is therefore to optimize the pulsed frequency of the pulsed light according to the reduction reaction rate on the reducing site of the enzymatic complex PSII and therefore according to the chemical nature of the electron sensor in order to have a number of turnovers per unit time as high as possible, and therefore of the number of Kok cycles per unit time.
Unfortunately, if the method of the state of the art puts forward promising conclusions as regards an optimization route of the operation of the enzymatic complex PSII, it remains nevertheless limited to a major constraint in the requirement of having a source of light of constant energy in time and sufficient for saturating the Kok cycle of the enzymatic complex PSII, the energy level of the light source being governed by the physicochemical nature of the enzymatic complex PSII, in particular by the chemical composition of the electron capture and donor groups.